Decipher the width of the X(3872) via the QCD sum rules

In this work, we take the X(3872) as the hidden -charm tetraquark state with both isospin I = 0 and I = 1 components, then investigate the strong decays X(3872) -> J=psi pi+pi-, J=psi omega, chi c1 pi 0, D*0 over bar D0, and D0 over bar D0 pi 0 with the QCD sum rules. We take account of all the Feynman diagrams, and acquire four QCD sum rules based on rigorous quark-hadron duality. We obtain the total decay width about 1 MeV, which is in excellent agreement with the experiment data Gamma X = 1.19 +/- 0.21 MeV from the PDG, it is the first time to reproduce the tiny width of the X(3872) via the QCD sum rules, which supports assigning the X(3872) as the hiddencharm tetraquark state with the JPC = 1++.